Alaskan Way Viaduct: Tunnel vision

SEATTLE POST-INTELLIGENCER EDITORIAL BOARD

Published
10:00 pm PDT, Thursday, August 17, 2006

An aesthetic argument for replacing the Alaskan Way Viaduct with a tunnel seems easy enough to make. But since the tunnel option would cost at least $1 billion more than replacing the viaduct with another elevated structure, the economic argument is the more difficult -- and telling -- one to make.

An economic case for the tunnel was offered Wednesday by the Downtown Seattle Association, which hired economist Glenn Pascall to estimate the hard cash benefits of eliminating the existing structure and putting the traffic underground.

He figures that spending the extra billion or so would increase area property values by $450 million, stimulate as much as $2 billion in additional property development and generate as much as $325 million a year in tourism.

Taxing those increased property values through a local improvement district could generate an additional $250 million, which could be used to offset tunnel costs. It's uncertain where the rest of the money would come from.

His figures seem defensible, but Pascall also notes there are two other crucial components to this huge public policy question. One is the state of "shock and awe" over looming construction disruption and how well the state and city can mitigate its impacts. The other is the likelihood voters will be asked if they support spending more money to put the viaduct underground on the same ballot that will ask them to fund a $1.6 billion city transportation package.